This is not primarily a research proposal although it facilitates the continuity of a number of research projects; the object is to maintain an animal resource (mouse) consisting of unique inbred lines, linkage and mutant stocks and certain named inbred lines. Breeding pairs are made available to qualified investigators on request. Among the stocks maintained are: Inbred Stocks: PHL atat bb lnln; PHH aa lnln; TH atat; TL AwAwbb; SF, Slowly Fertile, 2 lines; QF, Quickly Fertile, 2 lines; NAW-Miwh/mibw-wa-2, 20; Non-inbred stocks: z-cplus- wa. Mutant genes and tester stocks Sld, Steel-Dickie; d, Dilute; se, Short-ear; s, Piebald; hr, Hairless; si, Silver; av, Ames waltzer; pa, Pallid; bp, Brachypodism; Sd, Danforth's short tail; Ca, Caracul; hl, Hair-loss; bt, Belted; N, Naked; Re, Rex; M, Misty; b, Brown; Pt, Pintail; Ay, Yellow; le, Light ear; miew, Eyeless White; lx, Luxate; Ph, Patch; Blt, Light; an, Anemic; Wv, Viable dominant spotting; Congenic mutants: Miwh, White; Slgb, Grizzle-belly; Sp, Splotch; wa-2, Waved-2; To, Tortoiseshell; mibw, Black-eyed white; ae, Extreme non-agouti; at, Black and tan; Fu, Fused; v, Waltzer; ru, Ruby-eye, N2F4; je, Jerker; ln, Leaden; fz, Fuzzy; sr, Spinner; f, Flexed-tail; Va, Varitintwaddler; W, Dominant spotting; Bn, Bent-tail; Ta, Tabby; p, Pinkeyed dilution; c, Albino; pn, Pugnose; cch, Chinchilla; pun, P-unstable; Translocation stocks from Harwell: Tl45H, Tl63H, T6, (Tl; xCt), Cattanach's translocation; Pink eye stocks from Harwell: p6; pbs, (also known as p24), P-blackeyed sterile; p25; pd, Dark pink eye.